1. Field of the Invention
The present invention relates to a sound-scale generation device announcing a fixed time and a time-announcing clock.
2. Description of the Related Art
There has been known a 12-sounds scale generation device optimal for acoustic training (for example, see Japanese Unexamined Utility Model Publication (Kokai) No. 3-11275). Such the 12-sounds scale generation device generates a basic sound of one sound of the 12-sounds scale at a fixed time, then generates a predetermined scale-forming-sound corresponding to that time. A user can listen to the basic sound and the scale-forming-sound and recognize the time based on the basic sound, scale-forming-sound, sound-interval, and predetermined correspondence between sound-intervals and times.
Here, the difference in pitch between two sounds is called as a “sound-interval”. When a ratio of vibration numbers (frequencies) of two sounds physically is 1:2, the two sounds are said to be in the relationship of an octave. The above 12-sounds scale generation device generates two sounds by a melodic interval where the two successively reverberate. On the other hand, a sound-interval where two sounds simultaneously reverberate is called as a “harmonic interval”.
The sound-intervals of two sounds in an octave may be roughly classified into consonant intervals and dissonant intervals. A consonant interval is an interval giving a pleasant feeling by the fused state of two sounds when two sounds reverberate like a harmonic-sound, while a dissonant interval gives an unpleasant feeling (for example, see Tamura N., Outline of Music, Ongakunotomosha, May 31, 1956, pp. 122 to 123).
In more detail, intervals between a basic sound and time-announcing sounds which are scale-forming-sounds corresponding to the respective times, are categorized into perfect consonant intervals, imperfect consonant intervals, and dissonant intervals. In the above 12-sounds scale generation device, when generating a dissonant interval and imperfect consonant interval at predetermined times, the user sometimes finds the sound heard to be unpleasant. This unpleasant sound is generated repeatedly when the predetermined time arrives, so a sound-scale generation device or time-announcing clock eliminating this unpleasantness is desired.